Method and means for controlling electric discharge tubes



Feb. 2, "1943. A. H. IBIQRZA'CKENSEY 2,309,883

METHODAND MEANS FOR CONTROLLING ELECTRIC DISCHARGE TUBES Filed July '6, 1940 2 Sheets-Sheet 1 INVENTOR: 4 AUGUSTE HARRY BRACKENSEY ATT'ORNELS Feb. 2, 1943. A. -H. BRACKENSEY 2,309,333

METHOD AND MEANS FOR CONTROLLING ELECTRIC DIS CHARGE TUBES Y Filed July 6, 1940 Sheets-Shee't 2 INVENTOR AUGUSTE HARRYBRA'CKENSEY ATTORNEYJ Patented Feb. 2, 1943 METHOD AND MEANS FOR CONTROLLING ELECTRIC DISCHARGE TUBES Auguste Harry Brackensey, London, England, assignor of one-half to The Franco-British Electrical Company Limited, London, England, a

British company Application July 6, 1940, Serial No. 344,206 in Great Britain July 18, 1939 7 Claims.

This invention relatesto the control of the luminous output of electric discharge tubes or other electrical apparatus utilizing alternating current and is particularly applicable to the control of the luminous output from electric discharge tubes.

It has been appreciated that for certain advertising display signs, it is desirable to obtain from an electric discharge tube, a luminous output which cyclically changes so that in one complete cycle of the change the luminous output proceeds from a maximum point down to a minimum and then builds once more to a maximum.

According to the invention, an impedance is provided on the primary side (or even the secondary side) of the supply transformer of the electric discharge tube or in the supply circuit of other electrical apparatus, means being arranged in association with said impedance cyclically to vary the efiective reactance thereof to produce the desired cyclic changes in the luminous output of the associated tube or tubes or other electrical apparatus.

The impedance preferably consists of an inductance, the iron circuit of which is modified cyclically by the employment of a swinging pendulum-like armature or a rotating armature. Where it is desired to control a bank of discharge tubes in such manner as to produce a running shadow eilect or equivalent running band of more intense light, a plurality of the inductances referred to above may be disposed around a rtating armature or shield, which in turn influences the circuit of each inductance so that as the armature or shield passes by said inductance it causes the tube associated therewith either to have an increased or reduced reactance.

In order that the invention may be clearly understood and readily carried into effect the same will now be more fully described with reference to the accompanying diagrammatic drawings in which:

Figure 1 illustrates a system for controlling a bank or series of electric discharge tubes so as to give a ripple effect to the bank or series.

Figure 2 illustrates the application of the invention to the control of an ordinary electric lamp.

Figure 3 illustrates the control of an electric discharge tube by means of a pendulum-like armature.

Figure 4 illustrates the application of the invention to a flashing or signalling device.

According to the arrangement illustrated in Figure l, each discharge tube I has included in can be of the usual commercial voltage.

the primary circuit of the high-tension transformer 2 which supplies it, a choke 3, which is of the ordinary wound type and has a laminated iron core of U-shape. The chokes are arranged circularly around a rotary laminated armature, which revolves about a bearing 5, and are so disposed that the open ends of the U-shaped cores are radial with respect to the armature. Associated and revolving with the armature 4 is a counter-weight 6, both being in the form of segments in the example shown. The chokes are disposed very close to the segments 4 and 6 with as small an air gap as practicable. The sign represents an alternating current supply which The armature is adapted to be rotated by means of any prime mover, such as an electric motor, clockwork motor, etc. It will be understood that upon rotation of the armature, the segment 4 first comes opposite the U-shaped core of one choke and then opposite to the next and so on progressively around all the chokes. With current passing through the various chokes and transformers, then as the armature comes opposite the core of a choke, that choke has its reactance gradually increased up to a maximum point and then the reactance decreases once more as the armature continues to rotate. The current in the circuit will thus be diminished and increased gradually, depending on the rate at which the laminated armature 4 passes across the base of the pole pieces of the chokes. Each tube of the bank will therefore be dimmed progressively, such dimming representing a gradual change in the luminous output for each tube.

If it is desired that two rippling or running shadows should pass across the bank simultaneously, the one following the other at a predetermined interval in semblance of waves upon water, the part 6, instead of being a counterweight, is a duplicate armature. As shown in Figure 1, the armature 6 is disposed diametrically opposite to the armature 4 so that the second ripple is out of phase with the first. Depending upon the construction chosen, any number of armatures may be employed in the manner indicated.

Figure 2 illustrates the application of the invention to the control of an electric lamp. The light emitted by the lamp 1 will fluctuate in accordance with the speed, etc, of the armature. In this case also it will be understood that any desired number of armatures could be arranged to act upon the lamp.

In Figure 3, there is illustrated an arrangement in which the armature B is in the form of a pendulum and oscillates about the pivot 5 across the face of the choke 3. This principle can of course operate equally well on two or more chokes.

In the above, reference has been made to the progressive dimming and brightening of electric discharge tubes. If so desired and with a choke having an inductance of suitable value, the dimming may continue until the tube is extinguished, so that in efiect a flasher is produced. An arrangement for producing such an efiect is illustrated in Figure 4. Given that the armature 4 and counterweight B, revolve at a set speed, the chokes 3 could be connected either with high tension transformers operating neon beacons, arcs when the choke 3 would be provided in the primary of the transformer, or with other lamps suitable for continuous signal flashing. With the arrangement illustrated, it will be obvious that the signal given would be (dash, dot, dot, dash).

The advantage of forming a flasher in this way will be understood when it is considered that circuit-breaking Moreover, the critical extinction and ignition point of tubes varies, depending upon the physical characteristics of the tubes, e. g. the nature of the fillings, the pressures of the fillings and so on.

Thus, it is possible to work a combination of tubes, for instance some neon filled and others mercury filled, in such manner that some tubes flash and others dim and brighten periodically, as desired.

It will be appreciated that following the principles of the .invention, various constructional changes might easily be made to obtain Very varying effects upon a bank of discharge tubes. Instead of revolving the armature relatively to the chokes, the armature may be stationary and the chokes made to revolve.

It will also be understood that it is within the scope of the invention to design an impedance element in which the reactance decreases as an armature is brought near to the element, or the armature may be replaced by a magnetic shield-.

ing device which disturbs the iron circuit in an inductance.

The invention is not limited to employment in conjunction with discharge tubes and is applicable to other electrical apparatus such as filament lamps, are lamps, heating coils and the like.

What I claim and desire to secure by Letters Patent of the United States is:

l. A method of producing a running shadow effect on a bank of electric discharge tubes, which consists in connecting the same on the high tension side of a power supply circuit in order to associate the same therewith, including a plurality of inductances in the low tension side of said power supply circuit by connecting a group of iron cored chokes to said low tension side and disposing said chokes in a circle about a common center, and influencing the magnetic circuit of each inductance in turn and thereby causing the electric discharge tube respectively associated therewith to have an increased reactance by-rotating an armature upon said common center within the circle formed by said group of chokes and causing said armature to pass each inductance successively so as to influence the same in turn.

2. A method of producing a ripple effect on a bank of electric discharge tubes, which consists switches will be eliminated.

in connecting the same on the high tension side of a power supply circuit in order to associate the'same therewith, including a plurality of inductances in the low tension side of said power supply circuit by connecting a group of iron cored chokes to said low tension side and disposing said chokes in a circle about a common center, and influencing the magnetic circuit of each inductance and thereby causing the electric discharge tube respectively associated therewith to have an increased reactance by rotating two armatures synchronously in succession, said common center within the circle formed by said group of chokes and causing each of said armatures to pass each inductance successively so to influence the same in turn by each armature and thereby cause two running shadows to pass successively across said bank of electric discharge tubes.

3. A method of producing a ripple eifect on a bank of electric discharge tubes, which consists in connecting the same on the high tension side of a power supply circuit in order to associate the same therewith, including a plurality of inductances in the low tension side of said power supply circuit by connecting a group of iron cored chokes to said low tension side and disposing said chokes in a circle about a common center, and influencing the magnetic circuit of each inductance and thereby causing the electric discharge tube respectively associated therewith to have an increased reactance by rotating two diametrically opposite armatures synchronously in succession, said common center within the circle formed by said group of chokes and causing each of said armatures to pass each inductance successively so to influence the same in turn by each armature and thereby cause two running shadows which are out of phase with respect to each other to pass successively across said bank of electric discharge tubes.

4. A method of controlling the luminous output of an electric discharge tube, which consists in connecting the same on the high tension side of a power supply circuit in order to associate the same therewith and thereby virtually produce a flasher, including an inductance in the low tension side of said power supply circuit, consisting of a choke having a fixed U-shaped iron core, and cyclically closing the air gap magnetically between the ends of said U-shaped core in order to vary the reactance of said inductance sufliciently to cause the luminosity of said electric discharge tube to be periodically extinguished.

5. In connection with a high tension power supply circuit, an electric control system comprising a plurality of electric discharge tubes each connected on the high tension side of the associated power supply circuit, a plurality of inductances consisting of wound chokes with laminated iron cores, each connected on the low tension side of the power supply circuit, and a rotating armature around which said inductances are disposed circularly with the open ends of said cores radially directed towards the armature.

6. In connection with a high tension power supply circuit, an electric control system comprising a plurality of electric discharge tubes each connected on the high tension side of the associated power supply circuit, a plurality of inductances in the form of chokes with iron cores of substantially U-shape, each connected on the low'tension' side of the power supply circuit, and

a plurality of rotating armatures around which said inductances are circularly disposed.

'7. In connection with a high tension power supply circuit, an electric control system comprising a plurality of electric discharge tubes each connected on the high tension side of the associated power supply circuit, a plurality of inductances in the form of chokes with iron cores of substantially U-shape, each connected on the low tension side of the power supply circuit, and two diametrically opposed rotating armatures around which said inductances are disposed circularly with the open ends of said cores radially directed towards the armatures.

AUGUSTE HARRY BRACKENSEY. 

